A self-energizing brake is determined by the servo rotation of the brake drum with respect to the brake assembly mounted to that drum. When the brake is applied while the drum rotates in the opposite direction of the wrap of the outer brake shoe (the servo direction) a vast increase in braking effect is generated over that which can be expected from the normal brake actuating forces. The brake is then self-energizing. If the drum is rotating in the same direction of the wrap of the outer shoe, the drum is in anti-servo rotation and the brake is non-energizing. The same rationale applies to linear brakes where the braking surface travels through the brake in linear directions.
For emergency braking or when a brake is required to stop a load as fast as possible, a brake configured as self-energizing may be used. For more controlled braking where maximum consistency and smoother stopping is desired, a non-energizing brake should be used. After concluding which configuration is most appropriate for the particular application requiring braking, a determination can be made whether a left or right hand brake should be used based upon the direction of rotating or moving members of the application.
